Believe
by ObsessedShadowhunter
Summary: So things get heated after the visit to the Wayland Manor. Whatever will happen? Fluff and smut. DON'T READ IF YOU'RE NOT OLD ENOUGH! The first part of the story is  mostly  direct from COG and a line from COA. I own nothing... sadly.
1. A Little Hot and Bothered

They lay in the grass among the rubble of the Wayland Manor. Jace lay over her, his body flat against hers, his heartbeat loud in her ears. As debris finally stopped raining down on them, Clary gasped for breath.

"Jace," she said softly.

He drew back slightly, propping himself on his elbows, and looked down at her. Even in the darkness she could see herself reflected in his eyes. "Are you hurt?"

"I'm fine." Without thinking, she reached up, her fingers brushing lightly through his golden hair. She felt him tense, his eyes darkening.

"There was grass in your hair," she said. Her mouth was dry; adrenaline sang though her veins. She rested her hand against his cheek.

Jace just continued to look at her. After a few seconds, Clary asked, "What are you thinking?"

"About my feelings for you," he replied softly, almost to himself.

Her eyes widened, shocked. "What do you mean?"

He was silent for a long moment, staring down at her. "You're my sister," he said finally. "My sister, my blood, my family. I should want to protect you- protect you from the sort of boys who want to do with you exactly what _I_ want to do."

Clary's breath caught. "You said you just wanted to be my brother from now on."

"I lied," he said. "There are some kinds of wounds you can get when you're a Shadowhunter- internal injuries from demon poison. You don't even know what's wrong with you, but you're bleeding to death slowly inside. That's what it's like, just being your brother." His voice turned lifeless. "God knows I tried, but I don't want anyone but you. I don't even _want_ to want anyone but you." He trailed his fingers lightly through her hair, fingertips brushing her cheek.

Clary's voice sank to a whisper. "I don't want anyone but you either."

She was rewarded by the catch in his breathing. "No more pretending," he whispered. "I love you, and I will love you until I die, and if there's a life after that, I'll love you then."

Clary's hand slid along his cheek. "I love you, too," she breathed.

At her words, his expression changed- there was a look on his face she'd never seen before, a sleepy, almost deadly light in his eyes. He let his fingers trail down her cheek to her lips, outlining the shape of her mouth with the tip of a finger. "You should probably tell me not to do this," he said.

She said nothing. She didn't want to tell him to stop. She was tired of saying no to Jace- of never letting herself feel what her whole heart _wanted_ to feel. Whatever the cost.

He bent down, his lips against her cheek, brushing it lightly- and still that light touch sent shivers through her nerves, shivers that made her whole body tremble. "If you want me to stop, tell me now," he whispered. When she still said nothing, he brushed his mouth against the hollow of her temple. "Or now." He traced the line of her cheekbone. "Or now." His lips were against hers. "Or-"

But she had reached up and pulled him down to her, and the rest of his words were lost against her mouth. He kissed her gently, carefully, but it wasn't gentleness she wanted, not now, not after all this time, and she knotted her fists in his shirt, pulling him harder against her. He groaned softly, low in his throat, and then his arms circled her, gathering her against him. All that existed was Jace- all she felt, hoped, breathed, wanted, and saw was Jace. Nothing else mattered.

She could feel the heat of him burning through his clothes and hers. She tugged his jacket off, and then somehow his shirt was gone too. Her fingers explored his body as his mouth explored hers: soft skin over lean muscle, his scars like thin wires, a map of a life of endless war.

Jace unbuttoned her coat, his fingers trembling. Pulling back for a moment, his tawny eyes met her green ones. Sliding his hands slowly up her sides under her sweater, he brushed his lips over hers, lightly at first, and her own opened automatically beneath the pressure. With a soft moan, she twined her arms around his neck, her hands knotting in his hair, and the kiss stopped being gentle and became fierce, all in a single moment like tinder flaring into a blaze.

Her sweater bunched beneath her breasts as Jace softly slid his hands over her bra. The front clasp came free on the third try, and Clary gasped when he grazed her distended nipples with his fingertips. His mouth moved over her jaw to her throat, leaving a trail of fire in his wake. Clary moaned, her nails raking gently down Jace's back, making him arch against her, his middle meeting hers unexpectedly.

They both stilled as their breath stuttered out on gasps. Jace was pressed intimately between Clary's legs, her ankles locked at the base of his back, his hands still beneath her shirt.

Pressing his forehead to hers, Jace murmured, his breathing ragged against her lips, "If we don't stop now, I don't know if I'll be able to later."

Burying her hands in Jace's golden curls, she pulled his mouth to hers. "I don't want to stop," she whispered. "I want to be with you. Forever."

How could he deny her? He didn't care if she was his sister- he'd fallen in love with her before they'd ever been told. He had his doubts about the truth of it. After all, he looked nothing like Valentine, nothing like Jocelyn. Clary looked exactly like her mother, with her red hair and emerald eyes- where had his tawny hair and eyes come from? They couldn't be siblings.

Unable to take the torture of her against him, he parted her lips with his tongue, kissing her passionately before ripping his mouth from hers and asking between clenched teeth, "Where?"

Clary pulled his stele from her back pocket. "At home."

A few moments later, they walked out of the portal and into the courtyard on the side of the Institute. When Jace hesitated, Clary took his hand and led him to the front door. Pressing her hand against the wood and meeting his eyes, she whispered, "In the name of the Angel, we ask entrance-"

The doors swung away from her hand, opening to the dark foyer. With a smirk, Jace took the lead, starting the elevator as soon as they were inside. Clary leaned against his side, content, confident in her choice. There was no going back now. She had made the decision to be with Jace, no matter what, and she was going to follow through.

When the elevator stopped, Jace wrapped his arm around her shoulders and led her down the hall to his room. He opened the door and Clary sighed. It was still spotless and bare except for the furniture.

"What?" Jace asked as they entered, shutting the door behind them.

"I'm going to take some pictures and put them in this room," she said thoughtfully. "It's so impersonal in here." She shook her head and smiled up at him sheepishly. "Sorry."

He said nothing, just cupped her cheek while his eyes showed how deeply he appreciated her attempt to make his room homier. He leaned down and kissed her lips softly. Leaning his forehead against hers afterward, he stroked his hands into her red hair. "I want a picture of us by the bed. Otherwise, I don't care."

"I'll get a camera as soon as everyone gets back from Idris," Clary breathed against his lips, distracted. She felt him tremble as she stepped closer to him.

When their bodies touched from shoulders to toes, Jace knew he couldn't take any more. His hand slid over her hip as the other tangled in the curls at the nape of her neck, pulling her mouth to his roughly. His tongue parted her lips, mimicking his desires, the sweet sound of Clary's elated gasp swallowed by his passionate onslaught. Clary wound her arms around his neck, pressing herself as close to him as possible. His hand slid under her shirt again, shoving it out of the way as his mouth left hers to travel down the column of her neck. Gently massaging her breast, he walked her to his bed.

Clary disentangled herself from him long enough to shuck her coat, sweater, bra and shoes, discarding them into a pile on the floor before she crawled onto the bed, lounging against the pillows patiently.

Jace quickly followed suit, his clothes and footwear joining hers. Clad only in his jeans, he lay down next to her and pulled her back into his arms.

Their tongues fought for dominion as they explored each others' bodies. Clary moaned against his mouth when he weighted her breast in his hand again, flicking his thumb over her nipple. When her hand came dangerously close to his top button, he grabbed her wrist and pinned it above her head, laying half over her. His eyes warned her that his control was slipping.

Biting her lip, she rolled until she was straddling him, the delicious heat of his arousal pressing against her womanhood. Jace growled, gripping her hips.

Curious, Clary shifted, rubbing her femininity against his manhood. Jace reacted accordingly, his hips lifting to grind against hers. Her eyes fluttered shut at the sensation of having him beneath her like this.

Her power, however, was short-lived. Before she could guess his intentions, Jace was completely over her again, fitted snuggly between her legs. He kissed her, hot and hard, before his lips traced a trail down her neck, over her nipples- both treated to a wicked tongue lashing- and lower. Clary threaded her hands through his hair, the curls twisting around her fingers.

Jace kissed along her pant line as he undid them. His tongue dipped into her navel as he pulled the offending garment down her legs and off, leaving her in a plain pair of boyshort panties.

Breathing raggedly and barely holding on to his tattered wits, Jace looked up at Clary. Her eyes were half-lidded, the movement of her chest erratic. She was the most gorgeous thing he'd ever seen.

And she was his.

Holding her gaze, he slid his hands up her thighs. She gave a stuttered moan in anticipation. Using his thumbs, he parted her folds and blew a stream of air along her slit. Clary arched in reaction, her grip on his hair tightening. He did it again, a cocky smirk curving his mouth as Clary's eyes rolled back in pleasure. Finally, he moved her panties aside to see her treasure.

She was pink and swollen, her labia shimmering with juices. Unable to suppress the urge, he slid a finger into her, biting down hard on his lip when she arched up, her paradise hot and tight around his digit. He slowly stroked her, gritting his teeth against his own need. Without any coaxing, she began to move her hips as he added another finger, riding his hand with abandon.

The mental image of her riding another part of his anatomy proved to be too much. His digits moving faster within her, Jace lowered his mouth to her most intimate place, his tongue teasing her clit as his unoccupied hand undid his pants and slid them off.

Needing her painfully, Jace sucked her clit into his mouth, flicking it with the tip of his tongue. Clary's moans became sobs of ecstasy, her hands gripping his hair.

"JACE!" Clary screamed as her walls contracted around his fingers. He watched her in fascination as she came, noting her clenched eyes, flushed skin, and her erratic breathing.

When she was done, Jace crawled up her body to kiss her. "I love you," he whispered tenderly against her temple, feathering kisses over her face.

"I love you, too," Clary answered in a soft, breathless voice. Then her hand slid down his chest and between them, her fingers curling around his erection…


	2. Intimacy and Water Games

"I love you, too," Clary answered in a soft, breathless voice. Her hand slid down his chest and between them, her fingers curling around his erection. Jace exhaled sharply through his teeth as she stroked him- slow, measured strokes meant to drive him mad. He was painfully hard, the caress of his boxers enough to send electricity through his nerve endings. The added sensation of Clary fisting him through his undergarment brought him to the very brink of his control. He hung from the thread, fighting to keep himself from letting go and taking her like an animal.

Then she slid her hand through the slit in his underwear, and the thread snapped.

With a growl, he pulled away from her to shove his boxers off and rip her panties down her legs. Then he was over her again, kissing her with wild abandon, groaning into her mouth at having her naked skin against his, being nestled snuggly between her thighs, the tip of his cock teasing her entrance.

Clary clutched at him, answering his sounds by lifting her hips, trying to force his entry.

Ripping his mouth from hers, Jace closed his eyes and bit his lip hard, willing himself to slow down. Meeting her gaze, he ran his hand down her cheek. "Are you sure? After this, there's no going back."

"I've never been surer about anything." Clary's eyes glowed softly, reflecting his face.

Kissing her softly, he rested his forehead against hers as he slowly slid into her, clenching his teeth as her tight sheath surrounded him. When he reached her virginal barrier, he paused. He was breathing raggedly, covered in a thin sheen of sweat from holding back. "I… I can't…"

Clary looked at him in wonder and adoration. Pulling his lips to hers to kiss him heatedly, she thrust her hips with a cry of pain as Jace cried out in shocked pleasure.

Jace stroked her cheeks, wiping away her tears. She smiled appreciatively. He let her adjust to the sting, then pushed into her to the hilt, and paused again so she could become accustomed to his size and the feeling of having him buried inside her.

He whispered words of love and devotion to her, telling her only truths, never sweet nothings. She replied reverently, kissing him often.

Then Clary moved against him, showing she was ready to continue, and Jace began thrusting, gently at first, then faster and harder as she demanded. Their sounds of pleasure echoed off the walls, driving their desire higher. They kissed fiercely, their tongues mimicking the movement of their lower bodies. She wrapped her legs around his back and he lifted up, taking her at a slightly different angle, thrusting deep. Clary's nails raked his lower back and he groaned as he pounded into her.

Jace heard the catch in her breathing and felt the tightening of her muscles just before Clary yelled his name, falling over the edge into bliss. A few more thrusts and he joined her, exploding into her, her name a mantra on his lips.

Collapsing against her, Jace kissed every part of Clary he could reach- her face, her hair, her wrists. She stroked his hair and held him against her as if afraid to let him go.

When their trembling subsided and their breathing calmed, Jace rolled off of her and got up. Picking her up bridal style, he carried her to the shower and turned it on. Setting her on her feet, he quickly grabbed two towels. Clary stepped into the tub with a contented sigh when he returned, and he quickly joined her, wrapping her in his arms and leaning his forehead against her hair.

Once Clary was sufficiently wetted down, Jace took his body wash and poured some into his hand, using it to wash Clary. Starting at her shoulders, he worked methodically, soaping her everywhere until she was covered in white suds. He pushed her under the showerhead to rinse as his dick throbbed, wanting her again. He ignored it, instead lathering shampoo into his love's hair. When the water ran clear, they traded places, and Clary washed him, hair first. She saved his straining hard-on for last.

When he was clean everywhere else, Clary poured a little more soap into her palm and stroked him. Jace's head fell back at the contact, fantasies from the past few months of a situation like this rushing through his mind.

From her knees, Clary watched Jace shudder in passion from her ministrations and smiled proudly. It was empowering to know she could affect him this way, even in her inexperience. She stroked him faster, the soap making it easy. Moving her head to one side, she let the water rinse him clean before taking the tip of him into her mouth.

Jace cried out her name as she sucked, taking him a little deeper into her mouth as his hands tangled in her hair. Running her tongue over the vein along the underside of his penis caused him to thrust forward unconsciously. Clary moaned low in her throat at the taste of him, and lifted a hand to tease the bottom of his shaft as she bobbed up and down, taking as much of him as she could between her lips.

Clary heard his breath turn from heavy to labored, and suddenly she was on her feet and Jace was kissing her passionately, holding nothing back. He nipped at her lips before moving down her neck and biting down, firmly but gently, on her shoulder, eliciting a choked moan from her.

"If you don't stop right now," Jace panted against her skin, "this shower will have been pointless."

"Really?" Clary asked wantonly. She didn't know where her confidence came from, and she didn't care. Pushing him lightly against the shower wall, she pressed herself against him, grinding her pelvis against his as she avoided his searching lips, not allowing him to kiss her. He groaned in frustration, and Clary gave a throaty laugh.

Tired of her game and wanting to ravish her, Jace grabbed her hips and switched their positions, pushing her forcefully against the wall and lifting her leg to his hip with one hand as the other cupped the nape of her neck so she couldn't escape and kissed her senseless. His prick slid along her heat, teasing them both. Clary wound her arms around him, holding him against her, moaning every time the head of his member made contact with her clit.

Unable to stand it, Jace slid his hand between her thighs, sliding a finger into her as he teased her clit with his rod. She moaned, but winced when he added another digit. He stilled immediately, only then remembering that she was sore. Angry at himself, he released her and reached back to turn off the water, which was starting to run cold.

Stepping out, he reached a hand back to help Clary over the edge of the tub before grabbing their towels. After handing one to her, Jace toweled off and went into his room to look for clothes.

Clary watched in confusion and fear. Had she done something wrong? Wrapped in her towel, she went to follow him, but he was storming back into the bathroom.

"Jace?" Clary asked hesitantly, trying to discern what had set him off. "What did I do?"

Jace froze and turned to look at her in shock. "You didn't do anything," he sputtered- which made Clary laugh inwardly, because he _never_ sputtered. "I hurt you."

Clary rolled her eyes. "I'm fine. Honestly." She smirked at him, trying to mime his bearing. "Spoiling our fun over a little pain." She giggled.

Jace stared at her, uncomprehending. Exasperated, Clary walked over to the sink where he stood naked and groped him, taking him instantly from half-flaccid to full attention.

"Unfinished business." She quirked her eyebrow at him.

He answered by making a grab for her. She danced out of reach and laughed, "Race you to the bed!" She giggled louder at his growl as she sprinted for the bed…


	3. Clary's Wisdom

As Clary raced for the bed, she leaned down to scoop up Jace's forgotten stele. Just as she went to fling herself onto the sheets, Jace caught up, catching her in midair and landing on the bed next to her. She grinned at him and held up the stele. "Let's see if my little idea works." She quickly traced an iratze over the skin between her ovaries on her lower stomach, wincing slightly at the burn on her sensitive skin. After a moment, she pushed lightly where she'd hurt earlier. There was still a very light sting, but it was no longer as severe as it had been.

She smirked at him, her own version of Jace's favorite expression. "Much better." Then she rolled on top of him, straddling his hips. "Now, where were we?"

Leaning down, she captured Jace's lips. He held her hips gently as he slowly explored her mouth with his tongue, being careful. But Clary didn't want careful. Grinding herself against him, she smiled when his hands tightened and he moaned into her mouth, kissing her harder. Proud of herself, Clary slid her hand down his chest to stroke him, finding him hard and ready for her.

Unable to help himself, needing to please her as she pleasured him, he slid a finger along her slit. She was already slick and hot, and her gasp was swallowed when he pressed his thumb lightly against her clit. Carefully sliding a finger into her, he growled low in his throat as she began moving her hips. He added another finger, bracing for her wince, but it never came. She just moved faster, riding his hand as she had done earlier.

Clary stroked him faster, her lips moving down to his neck to suck on his soft skin. She left a mark on his shoulder and leaned back to admire her work, letting her towel fall around her waist in the process.

Jace leaned up and caught a nipple in him mouth, tonguing it as he fingered her. Clary's control snapped and she positioned him beneath her as she slapped his hand away. Then she impaled herself on him, moaning loudly as he filled her, and Jace stilled, gritting his teeth to keep from exploding immediately. She was so tight, so wet, and he was torn between flipping her over and slamming into her over and over or letting her have her way with him. He decided on the latter, because she'd be in control, and would stop if she was hurting.

Throwing her head back and using her hands on his chest for leverage, Clary rode him, moving up and down over him. She moaned every time he slid into her, making it nearly impossible for Jace to control himself. With every stroke and grind, Jace could feel himself slowly slipping until, with a cry, Clary came, her walls gripping him tightly.

Unable to stop himself, Jace flipped Clary onto her back and pounded into her hard and fast, kissing her breathless and swallowing her sounds of ecstasy as her orgasm went on and on without relenting. With a final thrust, he fell over the edge with her, his hips pistoning against her a final time before he collapsed, trembling, on top of her.

Once he could move again, he rolled to the side, Clary's head pillowed on his chest. Drawing intricate shapes along her bare side, he contemplated their future.

"I can't be away from you again," Jace whispered suddenly against the top of her head.

Clary shifted to look up at him.

"The separation nearly killed me before. Now…" He gritted his teeth against the injustice. "I don't think I can live without you. And I can't pretend we're nothing but siblings. I can't bare the thought of you meeting someone else, loving him like I love you." He shook his head, his hand becoming a fist against her ribs. "I want to keep you. I want you forever. And it's _wrong_." Jace's voice broke on the last word, his eyes clenching shut at the realization of how impossible their situation was.

"Jace, look at me." Clary sat up and leaned over him, meeting his gaze when he unshuttered his eyes. "I will never love anyone like I love you. We _will_ figure this out." She stroked his cheek gently and smiled at Jace's doubtful expression."Have faith," she said. "The Angel would not give a gift like this if there wasn't a reason. I love you, and that won't change as long as I live." She feathered kisses over his face.

"Faith." Jace sighed before sitting up, pulling her with him. He looked at her, her long red ringlets falling into her emerald eyes, the freckles on her pale skin, and he _believed_. He believed with every fiber of his being that, somehow, they'd make this work.

Heaving himself up, he took her hands and helped her to her feet before tossing Clary her clothes. Dressing quickly, they shared one last passionate kiss before heading back to the garden next to the Institute to draw a portal back to Amatis's kitchen. Hand in hand, they stepped through.

They were greeted by Amatis, Maryse, Robert, and Luke, who looked at their linked hands and obvious closeness with disbelief.

Pulling Clary behind him at their expressions, Jace gave his signature arrogant smirk."Did you miss me that much?"

The adults began demanding answers to where they'd been and what they'd been doing but Clary and Jace just smiled secretively at each other and told them about the events at the Wayland Manor. When they finished this explanation, they begged for the right to sleep.

Jace left with the Lightwoods, but he wasn't gone long. As soon as Clary climbed into bed, he was there, pulling himself though her window, clad in a gray t-shirt and plaid pajama pants. Without hesitation, he joined Clary, cuddling her close as his eyes drifted shut in exhaustion. "I love you," he whispered into her hair.

"I love you, too," Clary whispered back. And with the lulling comfort of his heartbeat under her cheek, she fell asleep in the arms of her brother.


End file.
